Tritone Substitutions

One of the things I think is cool is that a standard chord sequence in Jazz is the ii7-V7-IM7 (e.g., Dm7-G7-CM7) which, if you do the tritone substitution turns into ii7-II♭7-IM7 so you get this nice little chromatic descending sequence happening in the bassline.

It’s also worth noting that when comping, the most important notes to be sure to hit are the 3rd (which expresses whether we’re major or minor) and the 7th (which gives the flavor of the chord), since the root is likely covered by the bass player and the fifth is implied by the 3rd (if you’re at a piano, try you can see this by, e.g., playing C-E-G-B in the right hand and C in the left, and comparing that to E-B in the right hand and C in the left. A jazz pianist soloing will likely do their melody line in the right hand and hit 3-7 with the left), so the tritone substitution will be made/implied by whatever the bass player does against that.

The other fun thing is to just vamp on a II♭7-V7 sequence. Some notable places you’ll encounter this in music you’ve heard include the Simpsons theme and the Beatles’ “I Am the Walrus.”

"Music theorists tend to bombard their audience with more information than nonexperts can swallow in one sitting." groaned the mathematician, in cognitive dissonance.

The earliest tritone substitution I know of appears in Scarlatti K420

https://www.youtube.com/watch?v=Nf3_NfuvK8Y

There are two tritones in 7-limit just intonation (7/5 and 10/7) and therefore two possible tritone substitutions. Here they're played successively

http://lumma.org/music/theory/demo/progs/TritoneProgressions...

It's a shame to describe the tritone sub for G7 as C# F G# B, when the proper way to spell it is either Db F Ab Cb or C# E# G# B. Of course, then you'd have to explain about enharmonic equivalence and how chords are usually spelled with every other note.

Question for music theory experts who are also coders: does it feel like understanding a programming language, or something else? Admittedly I've never really made any serious independent effort to learn it, or to retain whatever I tried to learn, but it is very difficult for me to even grasp a mental model of how understanding it is supposed to work, or feel, in my head.

I can read a piece of code and know how the bits affect one another. When I read basically anything on music theory it feels like a string of non-sequiturs basically. Maybe there's just some skill floor where that all starts to feel organized?

I asked some classical music people once if there was a history of harmony. Someone retorted that the modern concept of harmony was an inadequate way of understanding counterpoint, and that the primary concept should be voice leading, not vertical harmony. I suppose it makes sense — that our categories of musical analysis have histories, and it can be misleading to apply them out of context (as the rest of this thread is commenting).

But I still wish someone would write a history about "what kinds of harmonies do people think sound good/melodious/interesting, and which do they consider bad/ugly/weird/useless at a given moment." Or if that history already exists, I wish I knew how to find it.

Interesting. John Baez is the brother of Joan Baez, the famous singer. Didn't know he was into music too.

That being said, Tritone substitutions sound good in some circumstances, but seem over the top in others. Use with care, as always. They'll always seem more appropriate in jazz genres

Music used to be treated like a science… the pythagoreans, for instance, conducted the first hypothesis driven scientific experiment on a musical question (whether whole number ratios affected chords with bronze chimes). Descartes’ first book was all about music theory.

Does one normally learn any theory as part of learning to play an instrument?

I played in middle and high school concert band and took private lessons in addition to that for a few of those years.

I never learned a lick of theory from any of my instructors. Maybe because as a horn player you can't play chords. All I learned was to read notes and play my part. After a year of high school band I came to the conclusion that this was just work and gave me no enjoyment at all so I quit. Everyone seemed surprised.

>But never mind. What if we take my picture and rotate it 180 degrees? Then we get a new chord! This trick is called a tritone substitution.

I know tritone subtitution from music theory, and trying to grok this explanation. What does the "roation by 180 degrees" represent in this case?

Interesting article, but FYI, I'm not sure if it's because of my mild color blindness, but making out some of the colors on those first couple pictures is next to impossible.

> A tritone is very dissonant

I’m sure he didn’t mean it literally, but to be pedantic a tritone is only moderately dissonant. A minor second is very dissonant.

“A tritone is very dissonant, so the dominant seventh chord really wants to ‘resolve’ to something more sweet.”

“I see you shiver with antici——”

It’s not dissonance that makes you want to hear the completion of the sentence, rather, it’s grammar. If you play a tritone out of context, there is no need for it to resolve, but you can cast context around it by adding a resolution to a tonic just after. The tritone has a culturally-learned grammatical role in western music; and that role is not a universal law of aesthetics.

“——pation.”

neat!

Always love to see music theory content here. Nice find!